I'm assuming the the numbers coming after the variables are meant to be exponents, and if I'm wrong just let me know
-3x^4 - 2x^3 + 3x^2 + 3x^4 - 4x^3 + x^2, rearrange to have like terms in order
-3x^4 +3x^4 - 2x^3 - 4x^3 +3x^2 + x^2, now simplify
0 -6x^3 + 4x^2
She can buy a maximum of 12 books for her music class
just do whatever you did now
10% of 110 = 11
20%= 11 x 2 = 22
22
10% of 22 = 2.2
2.2 x 2 = 20% = 4.4
2.2/2= 5% =1.1
4.4+ 1.1
=5.5 pieces of candy left